<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	<style>
		@media only screen and (max-width:800px ) {
			body{
				background: red;
			}
			h1{
				color: white;
			}
		}
		
		@media only screen and (min-width:801px) {
			body{
				background: dodgerblue;
			}
			h1{
				color: yellow;
			}
		}
	</style>
	</head>
	<body>
		<h1>后盾人 人人做后盾</h1>
	</body>
</html>
